Abstract: The present disclosure relates to methods, systems, and devices for performing analyses of biological nanoparticles. More specifically, the present disclosure relates to methods, systems, and devices for performing single biological nanoparticle size determination on a sample while the biological nanoparticle is in transit through a microfluidic chip. In other aspects, the present disclosure relates to methods, systems, and devices for selectively capturing biological nanoparticles on a coated planar surface, the capturing being facilitated by centrifugation.